The Shelterer is one of the bosses provided by Stalwart Dungeons. It can be summoned within the End Dungeon by interacting with the Shelterer Altar. Killing it will reward you with Void Crystals, required for making Teleporters and Chorundum Armor.
Finding & Summoning the Shelterer
The Shelterer can be found inside the End Dungeon. It doesn’t naturally spawn, as it needs to be summoned instead, which can be done with a Nether Star. Search the outer End for the End Dungeon.
This Dungeon is perilous, as Propulk, a flying creature with a ranged base attack, inhabits it. When it hits you, you’ll be given the Levitation Effect, which can cause you to fall into the Void if you’re not careful.
One way to negate the Levitation Effect is by wearing Chorundum Armor, but chances are you haven’t obtained this. Propulk can be defeated easily with a Sword or Bow and Arrows. If you’re hit with Levitation, you can use a Fishing Rod to bring the Propulk towards you before striking them with a Sword.
Eventually, you should aim to break their Spawners, which there are 4 of around the edge of the Obsidian Tower in the center of the dungeon. Inside this Obsidian Tower is the Shelterer Altar, up a small staircase. Right-clicking this with a Nether Star will summon the Shelterer, which sits on the platform above.
Defeating the Shelterer
Once spawned, you can find the Shelterer inside a giant protective cube. In this form, the Shelterer can only be damaged by explosions. Surrounding the edge of the Dungeons is Cannons. By right-clicking Cannons, you can mount them, and if you’re holding TNT, it can be fired from the Cannon towards the Shelterer.
Around the Obsidian Pillar, there is also some blocks with a TNT icon on them. By right clicking them while holding TNT, an explosion will take place at the Shelterer, dealing damage to it.
To be safe, you should probably bring at least 2 stacks of TNT to the Shelterer. Although with some good aiming from the Cannon, you might be able to kill it with just half a stack.
When enough damage has been dealt, the protective box around the Shelterer will be removed. You’re free to then kill the final form of the Shelterer with any weapon of your choice. Doing so will reward you with Void Crystals.